<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>border</title>
    <style>
        .c1{
            width:400px;
            height: 200px;
            /* border: 1px solid red; */
            /* border:5px solid red; */
            /* border:5px dotted red; */
            /*border:5px dashed red;*/
            /*border-top-width: 10px;*/
            /*border-top-color: blue;*/
            /*border-top-style: dashed;*/
        }
        .c2{
            width:400px;
            height: 200px;
            /* border-width: 30px; */
            border:30px solid transparent;
            border-image:url(img/border.png) 30 round;
        }
        /* 用边框实现梯形*/
        .c3{
            width:400px;
            height: 200px;
            border-bottom:30px solid red;
            /* border-right:30px solid blue; */
            border-left:30px solid transparent;
            border-right:30px solid transparent;
        }
       /* 用边框实现三角形 */
        .c4 {
            width:0px;
            height: 0;
            border-bottom:30px solid red;
            /* border-right:30px solid blue; */
            border-left:30px solid transparent;
            border-right:30px solid transparent;
        }
        .c4-2{
            width:0px;
            height: 0;
            border-top:30px solid red;
            /* border-right:30px solid blue; */
            border-left:30px solid transparent;
            border-right:30px solid transparent;
        }
        /* 用边框实现扇形 */
        .c5{
            width:0;
            height: 0;
            border-bottom:50px solid red;
            /* border-right:50px solid blue; */
            border-left:50px solid transparent;
            border-right:50px solid transparent;
            border-radius: 50%;
        }


        .line{
            margin-top: 20px;
            height: 0;
            width: 100%;
            border: 2px dashed red;
        }
        .c7{
            width:400px;
            height: 200px;
            margin-top: 30px;
            /* border-width: 30px; */
            border:10px solid transparent;
            border-image:url(img/border.png) 30 round;
        }
    </style>
</head>
<body>
    <div class="c1">

    </div>
    <div class="c2">

    </div>
    <p>用边框实现梯形</p>
    <div class="c3">

    </div>

    <p>用边框实现三角形</p>
    <div class="c4"></div>

    <p>用边框实现倒三角形</p>
    <div class="c4-2"></div>

    <p>用边框实现倒扇形</p>
    <div class="c5"></div>

    <p>border-image</p>
    <div class="line"></div>
<div class="c7"></div>
</body>
</html>
